Two-dimensional coordination polymers, [M(C8H12O4)(C10H8N2)]center dot H2O [M = Co (1), Cd (2); C10H8N2 = 4,4-bipyridine, C8H14O4 = subaric acid] were obtained from the reaction of the metal salts, bipy and subaric acid at 180 C and characterized by elemental analysis, infrared spectrum, and single-crystal X-ray diffraction and surface photovoltage spectrum (SPS). The single-crystal X-ray diffraction showed that the subaric ligand in the two complexes exhibits two types of modes coordinating to transition metal ions, resulting in the formation of a 1D infinite chain along the c-axis. In addition, the results of SPS for complexes 1 and 2 indicate that these two complexes exhibit positive surface photovoltage responses in the range of 300-800 nm, which can be assigned to LMCT and MLCT, respectively. And the SPS of complex 1 also can be assigned to the d -> d* electronic transition. The SPS spectra of the two complexes are consistent with their UV-vis spectra. (C) 2010 Elsevier B.V. All rights reserved.